This is a (fairly large 5,1 centimeters in diameter) brooch) from the Reichsnährstand (a government body set up in Nazi Germany to regulate food production), more particularly from the Landesbauernschaft Alpenland, on occasion of the “Kriegserntedank an die Bäuerin” (Harvest Appreciation Female Farmers).
The basemetal of the brooch is zinc, with a copper colored gilt, that has (as is always the matter with these) lost partially its gilt color. In the centre is an Odal-rune, which was at the time of the third reich, associated with farmlife and ownership of (farm) land. The rune is on both sides flanked by wheat sheaves.
Overall the brooch is in very good condition. It would be hard to upgrade.